North Korea has said the release of a Hollywood comedy about an assassination bid on leader Kim Jong-Un is an "act of war".

Pyongyang has threatened the US with a "resolute and merciless response" unless the authorities move to ban the film, starring Seth Rogen and James Franco.

The Interview - released in the US on October 14 - sees the actors playing two tabloid TV journalists who land an interview with Mr Kim in Pyongyang but are then tasked by the CIA with killing him.

In a statement carried by North Korea's official KCNA news agency, a foreign ministry spokesman said the film was the work of "gangster moviemakers" and should never be shown.

Seth Rogen (L) and director Evan Goldberg promote The Interview

The spokesman said: "The act of making and screening such a movie that portrays an attack on our top leadership ... is a most wanton act of terror and act of war, and is absolutely intolerable."

It is not the first time Hollywood has poked fun at a North Korean leader.

In 2004 satirical action comedy Team America, a puppet version of Mr Kim's father, Kim Jong-Il, was depicted as a speech-impaired, isolated despot.

In the official trailer for The Interview, a CIA officer calls North Korea the "most dangerous country on earth", and briefs the Rogen and Franco characters on the cult of personality surrounding the Kim family dynasty.

Kim Jong-Un's regime has threatened a "merciless" response

"Kim Jong-Un's people believe everything he tells them, including that he can speak to dolphins, or that he doesn't urinate or defecate," the officer says.

Played by Korean-American actor Randall Park, Mr Kim appears in the trailer as an overweight, cigar-chomping dictator, surrounded by security guards.

The scenes set in Pyongyang were filmed in Vancouver.

In a recent interview with Yahoo Movies, Rogen, who co-wrote the script, said the idea for the film came from a discussion over how journalists with access to world leaders might have the opportunity to act as assassins.

He said: "We read as much as we could that was available on the subject ... We talked to people in the government whose job it is to associate with North Korea, or be experts on it."